1. Field of the Invention
The present invention relates to an electrical connector that has a plurality of connection terminals. More particularly, the present invention relates to an electrical connector with an improved alignment feature for employment in reliably connecting audio devices, such as car radios.
2. Description of the Related Art
Referring now to FIGS. 7 and 8, an electrical connector 1 includes a plug connector 3 mounted on a substrate 2, and a socket connector 4, which inserts into plug connector 3 to establish an electrical connection therebetween.
Plug connector 3 has a plug connector body 3a and a plurality of connection terminals 3b securely embedded in plug connector 3a. 
Plug connector body 3a has a recess 3c which opens at an end surface thereof. Plug connector body 3a has a locking part 3d that protrudes downward from a lower surface of plug connector body 3a. Locking part 3d aids in positioning and temporarily retaining plug connector body 3a with respect to substrate 2.
Connection terminals 3b are arranged in two rows at a fixed interval in plug connector body 3a. One end of connection terminals 3b protrudes in a socket connector insertion direction inside recess 3c of plug connector body 3a. The other end of connection terminals 3b passes through plug connector body 3a and is exposed on the lower surface of plug connector body 3a. The other end of each connection terminal 3b is electrically connected by soldering to a connecting land (not shown) formed on the surface of substrate 2.
Referring now to FIGS. 9 through 12, socket connector 4 includes a socket connector body 4a and a plurality of connection terminals 4b embedded in socket connector body 4a. 
Socket connector body 4a has a plurality of joining holes 4c which open on an end surface thereof allowing plug connection terminals 3b access to socket connection terminals 4b, during an assembly process.
Connection terminals 4b are arranged in two rows in the same manner as connection terminals 3b of socket connector 3. During careful assembly, socket connector body 4a of socket connector 4 is inserted inside recess 3c on plug connector body 3a of plug connector 3, one end of each connection terminal 3b fits inside each respective joining hole 4c of socket connector body 4a. 
As a consequence of this contact between connection terminal 3b and connection terminal 4b of socket connector 4, an electrical connection is achieved linking socket connector 4 to substrate 2.
During normal assembly and use, after mounting plug connector 3 onto substrate 2, socket connector body 4a of socket connector 4 is inserted inside recess 3c of plug connector 3.
Once socket connector body 4a is completely pushed inside recess 3c, each connection terminal 3b of plug connector 3 contacts each of the corresponding connection terminal 4b of socket connector 4, and connection of socket connector 4 and plug connector 3 is achieved.
As can be seen from this design, during proper insertion, the outer surface of socket connector body 4a is restricted in the direction perpendicular to the insertion direction by the inner wall of recess 3c of plug connector body 3a. 
Unfortunately, as shown by the tilted position A of socket connector body 4a in FIG. 7, when socket connector body 4a is inserted at a mis-aligned angle in the vertical direction with respect to recess 3c of plug connector 3, a lower end edge of socket connector body 4a contacts the end of connection terminals 3b of plug connector 3.
As a consequence, should socket connector body 4a be further inserted in an effort to achieve electrical connection, connection terminals 3b of plug connector 3 are bent, deformed, and may be broken. Resulting in undesirable equipment damage and expensive and costly repairs.
It is an object of the present invention to provide an electrical connector in which straight and non-damaging insertion is ensured by simple construction.
The present invention relates to an electrical connector having a socket connector engagable with a plug connector. The plug connector slides into a recess of the socket connector and is securely guided and aligned with connection terminals during insertion. Complementary joining parts on the inside of the recess and the outer surface of the socket connector engage, prevent the socket connector from damaging the connection terminals in the recess, and securely guide the socket connector during insertion and reuse.
According to an embodiment of the present invention, there is provided an electrical connector, comprising: a socket connector, a socket connector body and a plurality of socket connection terminals in the socket connector, the socket connector body including a plurality of joining holes, the joining holes communicating respectively between first ends of each the socket connection terminal and a first face of the socket connector body, at least a first joining part on a first outer wall surface of the socket connector body, at least a second joining part on a second outer wall surface of the socket connector body, a plug connector, a plug connector body and a plurality of plug connection terminals in the plug connector, the plug connector body including a recess on a back end of the plug connector body, second ends of each the plug connection terminals extending into the recess toward the back end, the second ends of each the plug connection terminal insertably aligned with respective the joining holes and the socket connection terminals, at least a third joining part on a first inner wall surface of the recess, at least a fourth joining part on a second inner wall surface of the recess, and the first and second joining parts positively engaging, and preventing a misalignment of the socket connector with the plug connector, by aligning with respective the third and fourth joining parts during an insertion of the socket connector body into the recess, thereby preventing damage to the plug connection terminals and enabling easy electrical connection between the plug connection terminals and respective the socket connection terminals.
According to another embodiment of the present invention, there is provided an electrical connector, wherein: the at least first and second joining parts on the socket connector body are first and second guide ribs, and the at least third and fourth joining parts on the plug connector body are at least third and fourth guide grooves, whereby the guide ribs positively engages and slides along the guide grooves during the insertion and prevents the misalignment.
According to another embodiment of the present invention, there is provided an electrical connector, wherein: the at least first and second joining parts on the socket connector body are first and second guide grooves, and the at least third and fourth joining parts on the plug connector body are at least third and fourth guide ribs, whereby the guide grooves positively engages and slides along the guide ribs during the insertion and prevents the misalignment.
According to another embodiment of the present invention, there is provided an electrical connector, wherein: the at least first and second joining parts are at least one of a guide groove and a guiding rib, and the at least third and fourth joining parts are the other of the at least one of guide groove and the guide rib, whereby the at least one positively engages respective the other during the insertion and prevents the misalignment.
According to another embodiment of the present invention, there is provided an electrical connector, wherein: the guide grooves extend parallel to the plug connection terminals, the guide ribs extend parallel to the plug connection terminals, the guide grooves aligned with at least one of the plug connection terminals, and the guide ribs aligned with at least one of the plug connection terminals, whereby the joining parts maximize an insertion force during the insertion along the plug connection terminals and ensure a secure joining.
The above, and other objects, features, and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.